The First Heat
by TheLesbianator
Summary: Sebastian walks in one to morning to wake the young master, only to find him very much awake already. This is pretty much just smut, not much plot. Also, omegaverse.
1. Chapter 1

"Young master, it is time to wake—" Sebastian stopped when he entered the room, the scent hitting him like a brick wall, and found his master very much awake. He crossed his arms after closing the door, admiring the sight—Ciel on his hands and knees, his ass in the air, pumping his cock into his hand and fingering himself, reeking of omega desire. He turned his flushed face to Sebastian, but didn't stop pleasuring himself. "I see your first heat has arrived. Shall I lock the manor up and leave you with the omega servants?" Sebastian inquired, feeling his own cock harden at the smell of his young master. He needed to leave soon, or he would be ramming himself into the boy.

Ciel didn't answer, just continued to look at Sebastian with heavy lids, sitting up to crawl over to the edge of the bed and climb down, his night shirt soaked with sweat as he approached his butler.

"Young master…" Sebastian warned, his erection now clearly visible. "If I don't leave now—" He inhaled sharply when the young Earl touched his prick, rubbing it gently through his pants. "Young master—"

"Quiet," Ciel ordered. "Don't you dare move." He had a fairly good grip on himself despite being fraught with desire and hormones—that's Ciel Phantomhive for you.

Ciel knelt at his servant's feet, his nose barely reaching crotch-level. He unbuttoned his pants with shaking hands, reaching into Sebastian's underwear to pull out his dick. He smiled hazily when he saw it, hot and big and dripping with pre-cum.

Sebastian watched his master, bewildered that he would he think of touching him like that. He realized at this point that they were definitely going to have sex, but he didn't want his precious young master to disrespect himself so. "Young master, please allow me to—"

"I said shut up." Ciel growled, before licking up the side of Sebastian's member. Sebastian moaned at the touch of his wet little tongue, darting around his cock with inexperience. He shuddered every time Ciel's hot breath caressed him, letting small moans escape from between his fangs.

Having been alive for thousands of years and frequently taking form as a human alpha, Sebastian had learned how to control his urges, but with Ciel mouthing over his cock, he wasn't sure he could hold back.

"Does it feel good, Sebastian?" Ciel muttered, looking up at his butler through thick lashes.

"Yes, young master." Sebastian breathed, running his fingers through Ciel's hair to reveal his purple eye. He felt the seal of the contract flare, and quickly removed his gloves with his teeth to prevent the seal from burning them up.

"I love it when you do that," Ciel moaned. "When you take off your gloves like that. I want…" He took a deep breath. "I want you to touch me with your mouth like that."

Sebastian bent down to pick the boy up, tossing him gently on the bed. He ripped open Ciel's shirt, buttons flying across the room. Lowering his mouth to his nipples, Sebastian carefully took one into his mouth, lighting clamping onto it with his teeth and pulling upward. Ciel gasped, caressing Sebastian's head as he played with his small, sensitive chest. Sebastian straightened up over the boy and spread his legs. He was about to bury himself inside Ciel when he got an idea, and stopped.

"What are you waiting for?" Ciel panted. "Fuck me!"

"I don't know, I don't think you want it." Sebastian mused.

Ciel blinked. "What? Are you going to make me order you to—" He stopped abruptly when he realized what his servant sought to reduce him to. "You want me to _beg_?"

Sebastian shrugged playfully, acting like he was in control of himself when really he was hanging on by a thread. "I'm just not sure you're thinking clearly. My young master wouldn't dare give up his virginity to a mere butler."

"I don't care about that," Ciel grunted. "My virginity doesn't matter, only the promise of my virginity matters."

"You don't want to save yourself for your mate?"

"No, I don't care." He repeated.

"Well, what if I'm not in the mood to cater to your desires?"

Ciel frowned. "Don't forget your place, demon." His eyes drifted down to the throbbing cock inches away from his opening, and he bit his lip, clearly feeling the effects of his heat. When he tried to scoot closer and grab his butler, Sebastian pulled away, causing the boy to whine in frustration.

Sebastian leaned his face close to his young master's. "Beg."

Ciel growled. "Fuck me, now! I order you!"

Sebastian's grin faded—he couldn't disobey an order. He slammed himself into Ciel with inhuman speed and he gasped in pain. "I would've gone easy on you if you'd simply done as I said, young master…" Sebastian whispered, thrusting harshly. "But now, I think I shall _fuck_ you until you faint, my lord." He hissed the words into Ciel's ear, delighting in the screams of pain and pleasure coming from the omega.

"W-wait—Ah!" Ciel started until he was silenced by Sebastian's mouth on his, roughly biting his lower lip and fucking him into submission. "Seb—!"

Sebastian snaked a hand over his mouth before he could finish—no talking meant no orders. He could hear Ciel's moaning as he pushed himself in and out roughly, and the obscene squishing noises from the slick drooling from Ciel's hole.

Sebastian felt Ciel tense up, and knew he was close to coming. He grasped Ciel's cock with the hand that was previously covering his mouth, and therefore most of his face, and jacked it furiously.

"Sebastian…" Ciel choked out a sob, and the older male looked up at the boy's face, streaked with tears.

Sebastian halted, letting go of the omega's penis and stroking his face affectionately. Ciel groaned in frustration, tears streaming down his cheeks. "Young master, are you alright?"

"U-ugh, why did you stop?" He sobbed. "I was almost there…" He looked at his throbbing member. "It hurts now!"

"Generally, crying is a sign to stop." Sebastian explained, suppressing a grin.

"No, that's not—it's just it—" Ciel looked into Sebastian's eyes. "It's amazing. It's like nothing I've ever felt before, I love it, I _need_ it!" He threw his arms around Sebastian's neck, pulling himself up to kiss his butler fiercely. "Fuck me, Sebastian, please…" He begged.

Sebastian held the boy's hips gently, and started to drag himself out slowly, before pushing himself in even slower. He kissed the Earl passionately, cutting off his erotic moans and mewls. Ciel's nails dug into his back, the feeling of being fucked so thoroughly driving him mad. Sebastian's cock was pressing everywhere inside him, and was moving so delicately that he could feel it throb along with his hole.

His penis ached and he whined, trying to thrust against Sebastian's stomach. He needed to come. "Sebastian… Touch… Touch me… please, please, touch me!"

"Yes, my lord." Sebastian breathed, tenderly grasping his young master's prick and slowly pumping.

"F-faster… God, faster, please! Harder!"

Sebastian ignored him, keeping his pace slow and intense. He listened closely to Ciel's breathing, paid attention to his movements and twitches, and right when Ciel was about to climax, he squeezed on his head, making the omega screech delightfully as he came.

Sebastian waited patiently for him to regain his senses before continuing to fuck him, but this time he picked up his pace, pounding into him again and stroking his member fast and hard. His could feel his knot starting to form, and pushed in as far as he could before coming.

Ciel moaned sweetly, relief temporarily washing over him as he felt himself being filled by the alpha. He laid still while Sebastian spurted into him, grunting softly.

"Sebastian…" He moaned. "Oh, Sebastian… Do I belong to you now?"

"Yes, you're mine now." Sebastian growled possessively, nipping at Ciel's lip.


	2. Chapter 2

Ciel pursed his lips. "That's… not good."

Sebastian frowned. "I suppose not, me being a servant."

"And a demon," Ciel added, sighing. "Alpha servants end up mating with their omega lords and ladies frequently, and vice versa. It shouldn't really be a huge problem. It's not as if the Phantomhive house is crumbling, so there's no real need for me to mate with a noble other than maintaining status."

Sebastian raised an eyebrow—he was thinking very clearly for someone in his first heat. He scooped up some of the 'slick' leaking from Ciel and licked his fingers, letting out a light chuckle. "Young master, may I ask why you have deceived me?"

"You don't need to call me that anymore, I imagine." He said, dodging the question.

Sebastian leaned close to his mate, pulling out of him and crawling onto the bed to cradle him. "If you wanted me to make love to you, you could have asked. There was no reason to fake a heat." He whispered into his ear, rubbing the oil around his stretched entrance.

"I… I don't know what you're talking about." Ciel huffed, blushing and looking away.

"I thought that you were a bit young to be in heat. But may I ask, where did you get the pheromones?"

"I bought them from a vendor in London, last week," He grumbled. "While you and Finny were picking up the flowers for the garden. A man was selling pheromones, that's what gave me the idea."

"Well-played, my lord." Sebastian snickered, kissing the younger male's forehead. "But you haven't answered my question. Why did you find it necessary to put on such a show?"

Ciel smirked. "It would have been no fun if I'd simply told you to fuck me one day. I figured it'd be more interesting to make a game of it. A challenge, even. I'm not surprised you saw through my act, though."

Sebastian laughed. "You never cease to amaze me, young master."

"I told you that you didn't need to call me that."

Sebastian grinned slightly. "Very well, _Ciel_."

Ciel felt the color drain from his face, hearing his demon say his name for the first time. The way he put emphasis on it was frightening, but also extremely exciting. Suddenly, a thought occurred to him. "Sebastian… Are you still going to eat my soul?"

"Yes." Sebastian answered without hesitation. "We've come too far to back out now."

"But… We're mated now." Ciel mumbled. "Don't you want to cherish me, and protect me?"

"Most certainly." The demon agreed, wrapping his arms around the boy tightly to prove his point. "You and I will be together for eternity. After all, I will only be devouring your soul."

"You… you bastard!" Ciel gasped, realizing what he was saying. "All this time, you let me think I was going to die!" He leapt out of bed angrily as Sebastian tried to contain his amusement. "Why didn't you tell me?"

"Those unwilling to die for revenge aren't worthy to become demons." He explained. "Therefore, it's usually kept a secret that a human that has its soul eaten becomes a demon. There are many humans who would gladly give up their soul for eternal life."

"But you need to make sure they're ruthless enough to be good demons." Ciel scoffed. " _Well-played, butler._ " He mocked.


	3. Chapter 3

"Ciel, we're going to be late." Sebastian sighed, glancing over at the young boy comparing two outfits.

"No we're not. You can get us there in minutes, can you not?" Ciel mumbled, trying to decide between the blue suit or the red one.

"Yes." Sebastian admitted, walking over to his mate and tossing the red suit on the bed. He held the blue fabric against Ciel's bare skin, wrapping it around him delicately. "This one. It matches your eye."

Ciel let his hand flutter up to his face, covering his blind eye. "When I become a demon, will I be able to use this eye again?"

"Certainly." Sebastian assured him, removing his hand and kissing his eyelid gently. "We should hurry." He sat the boy on the bed, dressing him quickly before lifting him into his arms and leaping from the window.

"Lord Ciel, the Earl Phantomhive." The servant announced as Ciel and Sebastian entered the ballroom, arms linked as was customary for mates. Lau approached them, Ran-Mao at his side as usual.

"Ohhhh, has the Earl finally taken a mate?" Lau teased.

"What do you mean 'finally'? I'm only fourteen." Ciel scoffed. "We'll be announcing our engagement later tonight."

"Congratulations." Ran-Mao said with her usual expression, taking Ciel's hand and squeezing it.

Lau's mouth dropped open. "I was only kidding, my lord."

"I wasn't." Ciel sighed.

"Well, then, congratulations to you, master butler." Lau smiled. "You've found yourself an exquisite mate."

Sebastian shuffled forward possessively, sensing ill intentions from the man. "Yes, I'm aware. What about you, Lau? You're getting a little old to still be single, aren't you?"

Before Lau could open his mouth to retort, the music stopped and silence fell over the room.

"Your host, Lord Alois, the Earl Trancy."

The blonde smiled charismatically as he descended the golden staircase wearing a red suit, and Ciel looked to Sebastian, thanking him for choosing the blue suit. "Welcome everyone. I'm so glad all of you could be here tonight. Please, enjoy yourselves, and there will be a special announcement later in the night." The crowd applauded as Alois joined them, shaking hands and making small talk.

Sebastian inhaled sharply when he smelled it—Ciel's scent. "Ciel," He whispered. "Are you alright?"

"Yes, I'm—what's the matter with you?" Ciel raised an eyebrow when he saw Sebastian's flushed face.

"You smell so good…" Sebastian leaned into the Earl, sniffing his neck, and jolted back when the scent grew fainter. "What…"

The intoxicating smell wasn't coming from Ciel… When Ciel had been in 'heat', those weren't his pheromones. The pheromones Sebastian was drooling over were from someone else.

"Earl Phantomhive, is your butler ill?" Alois asked, approaching the pair.

Sebastian covered his mouth to suppress a moan when the scent grew stronger. "No…" He muttered when he felt his pants tighten.

Alois' eyes widened when he saw the bulge in Sebastian's pants. "Oh, dear, let me find you two a spare room. Come along."

The three hurried out of the ballroom and down several hallways until Alois pushed a door open, letting the lovers inside before entering himself and closing it behind him.

"What are you doing?" Ciel asked, turning to look at the sneering blonde. "I'd like to be alone with my mate."

"Oh, but he's not your mate." Alois laughed, striding over to the demon and exposing his neck so Sebastian could inhale his scent. "He's mine."

"He most certainly is not!" Ciel growled.

"He's bonded to my scent. You bought those pheromones from Claude and used them to trick him into knotting you, even though you have no use for a man's knot yet." Alois moaned softly as Sebastian lost control, wrapping his arms around the boy and licking his neck. "However, I'm a few years older than you… And I'm almost in heat."

"Sebastian, stop it!" Ciel barked.

Sebastian managed to remove his tongue from Alois' skin just long enough to gasp out an apology. "Ciel… I can't… It's too much, I can't resist him. I'm sorry."

"You're a bloody demon! Control yourself!" Ciel yelled.

Sebastian ignored him, and started to unbutton Alois' shirt, his jacket already thrown on the ground.

Ciel huffed angrily and tore off his eye patch, opening his eye, cursed with the mark that connected them, the mark that allowed him to control his demon. "Sebastian! I order you to stop it!"

The man immediately stood, stumbling away from Alois and back to his master's side. "Ciel, Ciel, I'm so sorry—"

"Quiet." He ordered, not taking his gaze off of Alois, who was now pouting in front of the bed. "Why did you do this? What do you want with us?"

"I just want to have a little fun, that's all." Alois grinned, shedding his shirt and beginning to unbutton his pants as he walked closer. As he stepped out of his pants, Ciel noticed he was wearing lingerie, with his silk stockings clipped to a garter above his lacy panties, and blushed furiously. "Do you like them?" Alois purred, running a hand through the younger boy's hair.

"No!" Ciel snarled, slapping his hand away.

Alois' smile faded. "Claude." The larger demon stepped out of the closet, swiftly tying a gag around Ciel's mouth and holding his arms back. "I'm going to make Sebastian suffer, and you're going to watch."

"Mmf!" Ciel tried to yell through his gag.

Alois kept his eyes on Ciel as he took Sebastian by the hair, leading him over to the bed. When met with resistance, he shoved his hand into his panties to gather some of his slick and forced it into Sebastian's mouth. That was all it took to convince the demon, and tears formed in Ciel's eyes as he watched his mate—no, his _butler_ —kiss and lick at Alois' skin. He tried to look away, but Claude gripped his chin, making him watch as Sebastian removed the lace panties from Alois' body.

Alois laid face down on the bed so that his feet were just barely touching the floor, opening himself up enough for Sebastian to lap eagerly at the slick leaking from his hole. He could hear Alois moaning and Sebastian growling, and he cursed.

 _Is Sebastian really bonded to Alois' scent? Is that even how it works? I was the one he was with… He had sex with me, so shouldn't he be my mate?_ A million thoughts ran through Ciel's mind. _Can I make him stop without a verbal command? Sebastian, can you hear me?_

"Your highness, it appears the Earl has become aroused." Claude's voice tore through Ciel's concentration, and he was shocked to feel the bulge in his pants. "Shall I see to his needs?"

"Yes, please make sure he enjoys himself. After all, he is my _guest_." Alois pushed Sebastian's face away and waited patiently to be filled with something more than a tongue.

Ciel screamed through his gag and struggled relentlessly as Claude tore at his clothes, running his hands all over the boy's pale skin. _Sebastian! Stop him, Sebastian!_ Ciel begged with his mind, his eyes squeezed shut as Claude molested him.

"Ciel!" Sebastian yelled. He pulled away from Alois and swiped at Claude, his long claws breaking the skin and stopping the demon long enough for Sebastian to scoop Ciel up and jump through the window.


	4. Chapter 4

Sebastian sat on the edge of their bed, head in his hands as he listened to Ciel sob under the blankets. There was a soft knock on the door, and Tanaka entered quietly.

"Would you and the young master like something to drink? Perhaps some tea and warm milk with honey?" He inquired quietly.

"Yes, thank you." Sebastian smiled, rising to take the drinks from Tanaka. "That will be all for now." He turned back to the bed and saw Ciel crawl out from under the sheets, eyes red and puffy from crying.

He took the milk, sipping it quietly. "Tonight—"

"I'm so sorry, Ciel. I'll never let anything like this happen again." Sebastian said softly, reaching out to touch his mate but hesitating.

"You saved me from him… He was going to…" Ciel shook his head. "But you protected me. I'm sorry I wasn't able to protect you from Alois. I'm sorry he did that to you."

"Me too," Sebastian whispered, taking Ciel's hand. "I'm so sorry I lost control like that—"

"Stop." Ciel inhaled shakily, closing his eyes. "This was Alois and Claude's fault. We didn't want any of this to happen… right?"

"No, no, god no." Sebastian sighed, kissing his knuckles delicately. "We were supposed to announce our engagement tonight."

"It doesn't matter, word will spread. I'm sure the Marquess of Midford has received my letter." Ciel waved his hand dismissively, regaining his composure.

"Lady Elizabeth will be devastated."

Ciel snickered. "She'll get over it. There are plenty of young nobles out there for her."

"Yes, and it wasn't a perfect match, her being a beta…" Sebastian mused. "It would have been difficult for you to father a child, but impregnating you should be—"

"T-that's quite enough." Ciel stuttered, flustered by Sebastian's bluntness. He wasn't wrong, though—beta females mated with omega males rarely had more than one child, and the child was usually small and in poor health. The same was true for alpha females mated with beta males. Alpha males didn't mate with beta males, and beta females didn't mate with omega females—no children would come of pairings like that.

But with Sebastian, Ciel could have many children, once his heats came.

"What are you thinking about?" Sebastian asked. "Babies?"

Ciel blushed. "Yes. So?"

Sebastian chuckled. "You haven't even had your first heat."

"And yet you've already fucked me." Ciel replied curtly.

"Yes… that was a bad decision." He sighed. "To be fair, I was under the impression you were ready."

Ciel frowned. "Are you implying I'm not ready for such things? We sleep in the same bed, we dress in front of one another…"

"Because we're mates. That can't be undone." Sebastian explained. "But I haven't touched you in that way since."

"Why?" Ciel whispered. "You said… All I had to do was ask…"

"I decided it would be best to wait."

"That doesn't make sense! Why won't you—"

"Because I love you!" Sebastian yelled, exasperated. "I love you, Ciel, and I don't want to take advantage of you or hurt you. I didn't care before, but I do now."

"You're a demon!" Ciel scoffed. "Since when do you adhere to human morals?"

"You're human, and we're living in a human world, and I'm taking the form of a human, so…" He closed his eyes. "It's confusing for me too. I didn't think having sex with you would mate us."

"Sebastian…" Ciel whimpered, leaning against the older male's chest. "It's been a month since we did it. I want you."

"You'll be in heat any day now. You can wait."

"No," He whined, pulling his night shirt off and climbing into Sebastian's lap. "Please make love to me again. I want to feel you." He rubbed his ass against Sebastian's crotch.

"Ciel…" Sebastian warned, feeling himself hardening.

"Come on. Please. I need it." Ciel panted, feeling desire build up inside of him, stronger than he'd ever felt before. "I _need_ it, Sebastian." He bent his head to his mate's neck, rubbing against his skin to mark him with his own scent. "You smell good…" His hole felt wet, and he moaned as he bucked against Sebastian.

Sebastian laughed as the sweet scent filled the air around him—Ciel smelled so much better than that other brat. Lifting the boy up, he removed his underwear before lying him down on the bed. He wasn't sure if Ciel realized what was happening yet.

Ciel moaned loudly as Sebastian swept his tongue over his entrance. "F-fuck…"

Sebastian sucked and licked the slick from Ciel franticly, trying to consume as much of the sweet liquid as he could. After he'd had his fill, he moved his mouth to the young omega's little cock.

"Se-Sebastian!" Ciel gasped. "Oh my god, don't stop!" His eyes rolled back into his head from the pleasure, thrusting his hips into his mate's mouth. "W-what's happening to me? It feels so good, oh _god_ ,"

Sebastian raised his head and kissed Ciel. "You're in heat, my love. Not so calm and demanding now, are we?"

"It hurts, Sebastian," Ciel groaned. "Help me!"

Sebastian smiled. "What do you want me to do?"

"You know what I want!" Ciel whimpered, blushing. "Please, please give it to me…"

"Give what to you?"

Ciel panted as he moved his hands down to stroke himself. "Your… your cock. Please, Sebastian! I'll die if you leave me like this!"

Sebastian chuckled, spreading the boy's legs and slowly pushing into him. "You won't die, Ciel. I won't let you die." He gritted his teeth as he pried Ciel open, gripping his hips tightly to bury himself inside.

Ciel let out a satisfied moan, wrapping his arms around Sebastian as he was impaled. "Ahh… Sebastian…" He whispered, licking his lover's lips and forcing his tongue into his mouth. Sebastian bit his little omega's lip, eliciting a delicious squeal and driving him to thrust faster, harder.

"Ciel… _fuck_ , you're so hot…"

"Sebastian, I love it, I love it, ughh!" Ciel whined, moving his body to get a better angle, causing Sebastian's prick to hit his sweet spot. "Yes! Fuck me, fuck me!"

Sebastian obliged, groaning as Ciel's nails dug into his back, drawing blood as he pounded into him. He sped up his thrusts, faster and faster, until his cock started to grow larger. He pushed all the way inside of Ciel, and groaned as he came deep inside of the boy.

Ciel gasped as he felt Sebastian release inside of him, causing him to come, squeezing his ass to milk Sebastian's penis.

The two lay entwined like that, gasping and panting as they tried to recover from their orgasms.

"Again," Ciel moaned. "Let's go again."

"I'm still knotted inside of you." Sebastian snickered. "Be patient. I'll fuck you again, don't worry. I'll give it to you as much as you want, and then some. I'll fuck you until you're overflowing with my cum and your ass is aching."

"Ohh, yes…" Ciel sighed, kissing Sebastian deeply, mewling softly when he leaned down to lick and suck his nipples. "Yes…"

Sebastian smiled. "Looks like it'll be a long week."


End file.
